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(No Model.) 2 Sheets'S11eet 1.

B. H. FISHER. DYNAMO REGULATOR.

No. 449,245. Patented Mar. 31,1891.

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B. HQ'PISHER. DYNAMO REGULATOR.

No. 449,245. Patented Mar. 31, 1891.

UNITED STATES PATENT OFFICE.

EURNET" ll. FISHER, OF NElV YORK, N. Y.

DYNAMO-REGULATOR.

SPECIFICATION forming part of Letters Patent No. 449,245, dated March31, 1891.

Applicatioh filed September 15, 1890. Serial No. 365.077. (N0 model.)

To all whom it may concern.-

Be it known that I, BURNETT H. FISHER, a citizen of the United States,and a resident of New York, county and State of New York, have inventedcertain new and useful Improvements in Dynamo-Regulators, of which thefollowing is a specification.

My invention relates to a self-regulating dyname.

The object of the invention is to provide a dynamo in which the brushesare automatically adjusted to the proper position for least sparking andwaste of current, and whereby the motion for adjusting the brushes isobtained from that of one of the field-magnets. The object is also toaccomplish improved mechanical construction.

The invention in all its details is illustrated in the accompanyingdrawings, in which Figure 1 is a vertical and partial sectional view ofthe dynamo in the direction of the length of the shaft. The internalfield-magnet is not shown in section, neither is the shaft norcommutator. Fig. 9 is a similar view to Fig. 1, except that the plane ofsection is perpendicular to the shaft at the line X in Fig. 1. Fig. 3 isa similar view to Fig. 2, except that the section follows the line Y inFig. 1.

The device embodying the invention consists of the combination offield-magnets a, having consequent pole -pieces Z), between which is aring-armature c; an internal fieldmagnet (Z, fixed to the tube e, looseupon the armature-shaft f, and located between the bearings g andarmature-hub 7a; a brushholder '1 carrying the brushes j for thecommutator m, and mechanism, hereinafter-described, connecting the saidbrush-holder to the field-magnet (Z.

01 is a pin projecting from the pole-piece 0 of the internalfield-magnet (Z, and n is a sec ond pin projecting from the lowerpole-piece o of the same field-magnet. The pin a is attached to avariable weight 19 by means of a string q, passing over a pulley 9'. Thevariable weight 1) consists of several detachable small weightssupported upon the string q.

s is an arbor passing loosely through the upper pole-piece b, and havingupon opposite ends fixed cranks if and t, provided with len gitudinalslots a and'u. The pin '22 projects into the slot a, and the adjustablepin 0 projects into the slot 'u. The said pin c screws into thebruslrholder 2' to'a distance depending upon how much motion of thelatter is required for a given motion of the crank t.

The operation of the device is as follows: hen the neutral line changes,the internal field-magnet will change its position relatively to theexternal field -1nagnet. This change of position will turn the crank tslightly, and thereby, also, thelnush-holder If the pin 1: is onceadjusted so that the brushes touch the commutator at the neutral line,then any change of relative position of the internal field-magnet clwill cause auto matically such an adjustment of the brushes that theywill continue to remain on the neutral line substantially. The amount ofweight 12 required may be easily determined by putting on the maximumand then gradually taking them off until the machine runs satisfactorilywith variable load. The weight 17 should pull in such a direction as tooppose the magnetic attraction.

I claim as my invention- 1. A dynamo consisting of the combination ofstationary and movable field-magnets, commutatonbrushes, and means forcommunicating motion from the movable field-magnet to the said brushes.

A dynamo consisting of the combination of stationary and movablefield-magnets, commutator-brushes,and means for communicating motionfrom the movable field-magnet to the said brushes, said means consistingof an arbor engaging both with the movable fieldmagnet and with the saidbrushes.

3. A dynamo consisting of the combination of stationary and movablefield-magnets, commutator-brushes, and means for communicating motionfrom the movable field-magnets to the said brushes, said meansconsisting of an arbor engaging both with the movable fieldmagnet andwith the said brushes and passing through a pole-piece of the stationarymagnet.

4. A dynamo consisting of the combination of stationaryfield-magnetshaving pole-pieces, a ring'armatur-e between and in inductive relationto said pole-pieces, an internal fieldmagnet loose upon thearmature-shaft, pins enee of two witnesses, this 13th.;1nyof September,1890.

BURNETT H. FISHER.

Witnesses:

EDWARD P. THOMPSON, E. G. DUVALL, J r.

